As the dissemination of a 3 dimensional television (3DTV) is raging, demand or interest for 3D service and a study for the 3D service are vitalized.
In general, a 3 dimensional video provides a 3D effect using a principle of stereo vision of two eyes. Since a human feels perspective via parallax of two eyes, in other word, binocular parallax due to a space between two eyes apart from each other about 65 mm, the 3D video may provide the 3D effect and the perspective in a manner of providing a video, which makes a left eye and a right eye see a related plane video, respectively.
The 3D video display method includes a stereoscopic technique, a volumetric technique, a holographic technique, and the like. In case of the stereoscopic technique, it provides a left view image supposed to be watched by a left eye and a right view image supposed to be watched by a right eye. The stereoscopic technique enables to recognize a 3D video effect in a manner of making the left eye and the right eye watch the left view image and the right view image respectively using a polarized glasses or a display device itself.
As mentioned in the foregoing description, a 3D broadcast delivers the left view image and the right view image, respectively. And, a broadcast receiver makes a 3D video in a manner of properly processing the left view image and the right view image. Hence, it is necessary to have signaling information to process a 3D broadcast signal.
Meanwhile, a limited 3D video in a fixed view can be received by a legacy 3DTV receiver. Hence, it is difficult for a viewer to freely select a preferred view. This sort of problem may cause a problem in multi-view broadcast or an auto stereoscopic 3DTV as well.